Comparison of GNSS Solution Errors Using an Atomic Clock or Crystal Oscillator

2021 ◽  
Author(s):  
Vladimir Pudlovsky
Keyword(s):  
Atomic Clock ◽  
Crystal Oscillator

scholarly journals Remote Synchronization Experiments for Quasi-Zenith Satellite System Using Multiple Navigation Signals as Feedback Control

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Toshiaki Iwata ◽  
Takashi Matsuzawa ◽  
Kumiko Machita ◽  
Akiyoshi Abei
Keyword(s):  
Feedback Control ◽  
Control Method ◽  
Atomic Clock ◽  
Satellite System ◽  
Synchronization Error ◽  
Crystal Oscillator ◽  
Ground Station ◽  
Long Duration ◽  
Navigation Signals ◽  
The Stability

The remote synchronization system for the onboard crystal oscillator (RESSOX) is a remote control method that permits synchronization between a ground station atomic clock and Japanese quasi-zenith satellite system (QZSS) crystal oscillators. To realize the RESSOX of the QZSS, the utilization of navigation signals of QZSS for feedback control is an important issue. Since QZSS transmits seven navigation signals (L1C/A, L1CP, L1CD, L2CM, L2CL, L5Q, and L5I), all combinations of these signals should be evaluated. First, the RESSOX algorithm will be introduced. Next, experimental performance will be demonstrated. If only a single signal is available, ionospheric delay should be input from external measurements. If multiple frequency signals are available, any combination, except for L2 and L5, gives good performance with synchronization error being within two nanoseconds that of RESSOX. The combination of L1CD and L5Q gives the best synchronization performance (synchronization error within 1.14 ns). Finally, in the discussion, comparisons of long-duration performance, computer simulation, and sampling number used in feedback control are considered. Although experimental results do not correspond to the simulation results, the tendencies are similar. For the overlapping Allan deviation of long duration, the stability of 1.23×10−14 at 100,160 s is obtained.

scholarly journals Remote Synchronization Experiments for Quasi-Senith Satellite System Using Current Geostationary Satellites

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Toshiaki Iwata ◽  
Tomonari Suzuyama ◽  
Michito Imae ◽  
Yuji Hashibe
Keyword(s):  
Elevation Angle ◽  
Atomic Clock ◽  
Satellite System ◽  
Timing Synchronization ◽  
Tropospheric Delay ◽  
Experimental Setup ◽  
Crystal Oscillator ◽  
Synchronization System ◽  
Geostationary Satellites ◽  
Ground Station

The remote synchronization system for the onboard crystal oscillator (RESSOX) realizes accurate synchronization between an atomic clock at a ground station and the QZSS onboard crystal oscillator, reduces overall cost and satellite power consumption, as well as onboard weight and volume, and is expected to have a longer lifetime than a system with onboard atomic clocks. Since a QZSS does not yet exist, we have been conducting synchronization experiments using geostationary earth orbit satellites (JCSAT-1B or Intelsat-4) to confirm that RESSOX is an excellent system for timing synchronization. JCSAT-1B, the elevation angle of which is 46.5 degrees at our institute, is little affected by tropospheric delay, whereas Intelsat-4, the elevation angle of which is 7.9 degrees, is significantly affected. The experimental setup and the results of uplink experiments and feedback experiments using mainly Intelsat-4 are presented. The results show that synchronization within 10 ns is realized.

A Next-Generation, Miniaturized Rb Atomic Clock Reference for Mobile, GNSS-Denied Environments

2020 ◽  
Author(s):  
William Krzewick ◽  
Jamie Mitchell ◽  
John Bollettiero ◽  
Peter Cash ◽  
Kevin Wellwood ◽  
...  
Keyword(s):  
Atomic Clock ◽  
Next Generation

SEM/EDS Characterization of Uncommon Metal Whiskers and Determination of Underlying Growth Mechanisms

2018 ◽  
Author(s):  
D. Basak ◽  
L. H. Ponce
Keyword(s):  
Reliability Analysis ◽  
Case Studies ◽  
Whisker Growth ◽  
Innovation Systems ◽  
Growth Mechanisms ◽  
Crystal Oscillator ◽  
Analysis Laboratory ◽  
Investigative Techniques

Abstract Two case-studies on uncommon metals whiskers, performed at the Reliability Analysis Laboratory (RAL) of Northrop Grumman Innovation Systems, are presented. The components analyzed are an Oven Controlled Crystal Oscillator (OCXO) and an Electromechanical Relay. Investigative techniques were used to determine the chemical and physical makeup of the metal whiskers and develop an understanding of the underlying effects and mechanisms that caused the conditions conducive to whisker growth.

Magnetic shield integration for a chip-scale atomic clock

2020 ◽  
Vol 13 (10) ◽  
pp. 106504
Author(s):  
Hyun-Gue Hong ◽  
Jongcheol Park ◽  
Tae Hyun Kim ◽  
Hee Yeoun Kim ◽  
Sang Eon Park ◽  
...  
Keyword(s):  
Atomic Clock ◽  
Magnetic Shield
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